The present invention relates to semiconductor integrated circuit devices, and in particular relates to the technique effectively applied to a semiconductor integrated circuit device with an analog/digital conversion circuit block having a disconnection detection function.
Japanese Patent Laid-Open No. 1987-86724 (Patent Document 1) describes a configuration, in which in a signal combining circuit for combining an actual line and an auxiliary line at one terminal, a T-type switch is arranged in each of the actual line and the auxiliary line. This T-type switch includes a first switch and a second switch connected in series over the line, a third switch connected between the common connection node of the first and second switches and a ground power supply voltage, and additionally a resistor connected in parallel to the first switch. In switching the actual line and the auxiliary line, each switch is appropriately controlled.